Many dive sites are accessible by a boat ride of a few minutes to a few hours from shore, so you can go out to the site on a boat, dive and return to your land-based accommodation at night. Boats which conduct day trips range from rubber dinghies equipped with an outboard motor to larger boats with indoor areas and hot showers. Longer day trips tend to entail nicer boats. Dive trips that take much of a day will usually include a catered lunch and perhaps some smaller snacks in the price. On a per-dive basis day trips are usually more expensive than liveaboards, so divers choose to day-trip when they want to only have a few dives at a particular set of sites, or when they want to alternate diving with other activities.

As with liveaboards, some people take their first boat trip unaware of the possibility of sea-sickness. If you think you're at all likely to suffer (ie if you get sick in cars or other vehicles), you should take some preventative measures an hour before leaving on the boat. Some boat travellers use natural remedies like ginger, most use motion sickness pills available from pharmacists. However, these may cause drowsiness and should be used in moderation if at all — many divers find that symptoms of motion sickness disappear quickly once underwater. The choice will depend on whether you experience mild discomfort, in which case you may find that staying still and calm near the centre of the boat may alleviate symptoms (as will being underwater); or severe nausea, in which case medication might be the only way you can bear to get on a boat.

Be aware that not all day trip boats will have toilet facilities. Since it's not a good idea to dehydrate yourself before diving you may have to accept that you will have to urinate either over the side of the boat or into a bucket which you'll tip over the side and rinse. This can be a little more difficult for women to do quickly and safely. If this is unacceptable to you be sure to check on the boat's facilities in advance.